Southern Electric History and Infrastructure Part 4 - Re-Privatisation
The re-privatisation of British Railways created 27 passenger train operating companies. Three of the initial companies, Connex South Eastern, Connex South Central and South West Trains were nearly direct descendants of the South Eastern, Central and South Western traffic divisions of British Rail Southern Region from 1948, in turn from the Southern Railway from 1923, and of the pre-grouping London & South Western Railway, South Eastern & Chatham Railway and the London Brighton & South Coast Railway companies. Three other train operating companies, Gatwick Express, Thameslink and Island Line were also formed out of Network South East, while other operators also run passenger, and freight, services through the Southern Electric area.
In the near future, only South West Trains will remain from the original "Southern" train operating companies. The South Central franchise moved from Connex to Govia who named it (new) Southern Railway. The financial performance of Connex South Eastern was poor and the operation was temporarily taken back into public ownership as South East Trains until the franchise was awarded to Govia, who named it Southeastern Trains. Government policy of the time was to reduce the number of franchises to encourage less disjointed operation on shared lines, however perversely Govia, who had been running the Thameslink franchise sharing the Brighton line with Southern, then lost it to competitor First Group who then named the service First Capital Connect. The Island Line, run by Stagecoach Group, was integrated into South West Trains (also run by Stagecoach Group) and Gatwick Express is to become part of the South Central franchise. Following a perverse U-turn in government policy shorter franchises are now in vogue which does not encourage long term development by the private companies. Such is the merry-go-round of the modern privatised railway many would ask if the amount of time, effort and expenditure devoted to the franchise renewal process is producing a better railway than if all this was instead ploughed directly into developing the railway and running services?
The major development of the past five years has been the replacement of Mk1 slam door stock with modern microprocessor controlled units whose reliability and seat comfort has yet to approach that of the older trains. South West Trains opted for German/Austrian-built "Desiro" stock from Siemens whilst the Connex franchises, subsequently Southern and South East Trains/South Eastern opted for British-built "Electrostar" stock from Bombardier. The Island Line still retains its 1938 former London Underground stock!
The Channel Tunnel itself is not strictly part of the Southern Electric system due to its basis on private sector funding and operation by an independant company. However, the significant freight and passenger channel tunnel traffic flows fall directly within the Southern Electric area. Traditional channel ports passenger boat train flows were withdrawn when the tunnel opened, together with cessation of the Dover-Dunkirk train ferry. Dover Western Docks passenger station was also a casualty of the tunnel. International passenger services between London and Brussels and paris are operated by Eurostar. The channel tunnel was constructed by a consortium of civil engineering concerns known as Trans Manche Link. Trans Manche Link at one time operated the UK's third largest railway when its 600 mm gauge construction railway system was in full operation. On completion of the main railway was taken over by Eurotunnel who directly operate the shuttle truck and tourist services under the Le Shuttle name, and lease pathways to the British and French railways for passenger and freight services. Since the opening of the Channel Tunnel and rather belatedly a high speed route from the tunnel to London has been constructed in two phases. During construction it was known as the Channel Tunnel Rail Link but now its full length is in service it is marketed as "High Speed 1", Britain's only dedicated high speed train route.
Through all these operational, technical and political changes in over a century of Southern Electric operation, few electrified lines have been closed. The Crystal Palace High Level service was suspended then withdrawn after WW2 while the Haywards Heath to Horsted Keynes line was axed in the notorious Beeching cuts of the 1960s. (Horsted Keynes was a junction station with the non-electrified line which now forms part of today's Bluebell Railway). In more recent times the former SECR Holborn Viaduct London terminal station was closed for replacement by the through City Thameslink station as part of a major office development. Dover Western Docks was closed as a direct result of the completion of the Channel Tunnel, while both the Addiscombe to Elmers End and West Croydon lines were closed for replacement under the Croydon Tramlink project.
Following the closure of former Southern Railway power generating stations at Durnsford Road and Rotherhithe Road power for the Southern Electric system was purchased by the former British Railways from the former Central Electricity Generating Board and taken from the national grid at various locations. A network of lineside cables distributes power, mostly at 33kV 50Hz three phase AC, to lineside substations. These are generally located at intervals of about 3½ miles along each line, with intermediate track paralleling huts. Substations on the Bournemouth are 4½ miles apart due to the higher than usual voltage on that line. At each substation the alternating voltage is stepped down by transformers and the current rectified to direct current. It is then fed through switchgear to conductor rails, each laid on porcelain insulators 1ft 4in outside one of the running rails on each electrified track. Conductor rail is made of high conductivity steel and weighs between 100 and 150 lb/yd. Current is returned from the trains to the lineside substations through the running rails. Substations vary in design considerably, due to their differing ages, but all are unmanned and remotely supervised from one of ten electric control rooms located at strategic points throughout the region. Nominal line voltage varies from area to area and actual line voltage can fluctuate considerably. All types of multiple unit train subsequent to 1936 stock are able to accept the differing voltages without any special arrangements. Obviously, performance with DC motored stock is superior on the lines with higher voltages. Until 1939 lines were electrified at 600V except for some in the inner suburban area. Lines in Kent south and east of Gillingham, Sevenoaks and Maidstone, that is those electrified by British Railways, have been at 750V since electrification. The Weymouth line west of Bournemouth is electrified at 850V. The Isle of Wight line is electrified at 630V while the Waterloo & City [now part of the London Underground] remained at 660V. The Isle of Wight system is unusual in that power is purchased from the Southern Electricity Board, it obviously being impractical to connect the island to mainland power cables. The Southern's other island, Sheppey, is connected to the main lineside network by means of a cable under the River Swale, but power can be obtained from the South Eastern Electricity Board at Queenborough in emergency. In order to ensure that the lineside power supply equipment is not overloaded, all electric multiple units are allocated a "conductor rail current index number". This number is directly proportional to the maximum current likely to be drawn from the line by the stock concerned and in most cases is equal to the number of (250 hp) traction motors on the unit. The total index number must not exceed 16.
The newer Desiro and Electrostar stock has a far higher average current draw than the stock it replaced. Modern stock takes direct current, "chops" it to variable frequency alternating current which then excites the ac motors. Thus current draw is pretty constant compared to traditional DC stock where current is high upon starting and when "notching up" but then reduces as speed is gained. Since the turn of the century this has resulted in the power distribution network being upgraded to cope with the higher demands placed on it. Most modern stock is capable of regenerative breaking where the motors when braking generate electricity and can feed power back into the system, however experiments with this on the Southern Electric system are only just commencing.
Upon re-privatisation of the railways the train operating companies, except on the Isle of Wight", were not responsible for infrastructure, which was placed with a single national company - Railtrack. History has revealed that Railtrack placed more priority on being a property-led rather than an engineering-led operation and ultimately this led to a number of fatal accidents, the following public outcry and urgent corrective engineering work severely impinging upon the company's financial performance. Railtrack was taken back into public ownership as Network Rail. Network Rail has subsequently taken most maintenance and engineering work back "in-house" because the widespread use of contractors was not resulting in work being done as safely and reliably as it should.